Just an alternate currency. Unfortunately, and regardless of the fantasy world of bartering that I see on this site, one who walks around with a case of toilet paper will likely have trouble finding the proper size and style of boot they need to replace their worn out ones. It’s simply a lot easier with money. Pure bartering likely hasn’t existed for thousands of years, and if we ever try to go back to that, I suspect 98% cannot be supported (i.e., they starve).
So why and alternate currency? So that the taxing authorities can’t track (and tax) transactions.
Looks like they are using an alternative unit of measure for currency, and pure bartering doesn't come into the picture. I'm thinking you threw up a straw man.
/johnny